Influence of a short-range Coulomb potential on the photoelectron momentum distributions of F ⁻ ions within a semiclassical model in a few-cycle infrared laser pulse

The outermost electron in a F^- ion experiences a much weaker, short-range induced force, which has attracted widespread attention. By using an improved negative-ion quantum-trajectory Monte Carlo (NI-QTMC) model, which is a semiclassical method, we theoretically investigate how a short-range Coulomb potential affects photoelectron momentum distributions (PMDs) of F^- ions in a few-cycle infrared (IR) laser pulse. The PMDs present a series of concentric above-threshold detachment (ATD) rings emanating from the center and the recollision rings, which are consistent with those obtained by the fully quantum approach, demonstrating the feasibility of the NI-QTMC model. The results show that the short-range Coulomb potential primarily influences the rescattering photodetachment rather than the direct photodetachment of the F^- ion. The short-range Coulomb potential in Newton's equations plays an important role in the formation of the recollision rings. It can be demonstrated that, owing to the absence of Coulomb focusing in the short-range Coulomb potential, the variation of final longitudinal momentum with carrier envelope phase (CEP) is much weaker than that in the long-range Coulomb potential case. In addition, the short-range Coulomb potential can also influence the probability of electron emission in the forward and backward directions. Moreover, we can illustrate that the electrons emitted around <i>θ</i> = 90^∘ and <i>θ</i> = 270^∘ rarely change with the CEP in the case of the short-range Coulomb potential, which is related to the CEP-independent emission direction of rescattered electrons. Our results provide an analytical tool for investigating negative-ion photodetachment and broaden the scope of the short-range Coulomb potential in strong-field ionization.